808
JOHN F. DHEYER
the purity is 250 or higher. If the dominating ion is divalent, the behavior of the electrolyte is intermediate between the monovalent and trivalent ions, in accord with the Burton-Bishop rule. Although, for reasons previously noted, complete investigation could not be made of coagulation with a dominating trivalent ion, the data show that rapid coagulation values vary directly with the sol concentration, as has been expressed in the Burton-Bishop relation. Further investigation is being made of the trend toward a minimum coagulation value found when potassium sulfate was the added electrolyte. The cause of the scrambling of the coagulation values in some sols when the dominating ion was univalent is being investigated. REFERENCES
(1) BcRrroN, E. F.,A V D BISHOP,E.: J . Phys. Chem. 24, 701-15 (1920). (2) HOFFM~N, , A N D WANNOW., H. A . : Kolloid-Z. 83, 258-62 (1938). C. H . : J. Am. Chem. SOC. 62, 2598-2602 (1930). (3) JUDD,R. C . , ASD SORUM, (4) K a u ~ ~ ~ aV. s sH.: , Kolloid-Z. 93, 86-103 (1940). (5) M U K H E R J EJ. E ,s., A N D PAP%CO~STANTINOU, B. C.: J Chem. soc. 117, 1563-8 (1920). (6) SORUM, C . H.: J. Am. Chem. SOC.60, 1263-8 (1928). (7) T R O E L S T RS. A ,.4.,ASD KRUYT, H. R . : Kolloid-Beihefte 64, 225-6 (1943). (8) T U L L E RE. , F . : Doctoral thesis, Iowa State College, 1946. , P.: J . Phys. Chem. 49, 9 (1943). (9) T U L L E RE, . F . , A X D E B L I NL. (10) WAXNOV~, H . -4.: Kolloid-Z. 77, 46-53 (1936). (11) WANNOR,H. 8 . ,AND HoFFarANs, I
